I've decided to get a late 2013 15" rMBP to replace my faithful early 2008 15" MBP. My only config question is: What performance differences, if any, am I likely to notice if I go for the 2.3GHz i7 quad-core over the 2.0GHz version? My guess is "hardly any difference", especially since I don't do any processor-intensive gaming, graphics/video editing, etc, so I'm assuming I should save the $100 difference. The only thing I use my 2008 MBP for that really strains its processor is Skype/Google Hangouts video chatting. But I'm not that familiar with current processors, etc., so I'd be curious if there would be any advantages to a somewhat faster chip that I'm missing.